The existing luminous module of the headlight for motorcycle or automobile could be classified into tungsten halogen lamps, halogen lamps, or high intensity discharge (HID) lamps. Furthermore, “an automobile lighting device and light source module thereof” was disclosed in Taiwan Patent Publication No. M539600, wherein a light-emitting diode (LED) acts as a light source and replaces the existing tungsten halogen lamp, halogen lamp, or HID lamp. However, the heat dissipating effect of “the automobile lighting device and light source module thereof” still needs to be improved.
In Taiwan Patent Publication No. M536321, another “automobile lighting device and light source module thereof” was disclosed. In the art, low-beam illumination is produced by a first luminous component 12 located on a substrate 11 through a reflective shell 14. High-beam illumination is produced by a second luminous component 13 located on the substrate 11 through the reflective shell 14. However, according to the disclosure of Taiwan Patent Publication No. M536321, the substrate 11 is apparently a thick and fundamentally insulated heat-dissipating substrate. Further, referring to FIG. 1 and FIG. 2 of Taiwan Patent Publication No. M536321, each of the first luminous component 12 and the second luminous component 13 is fixed on a ceramic substrate and then further fixed on a metal core printed circuit board (MCPCB). Then, the MCPCB attached with the ceramic substrate and the first luminous component 12 (or the second luminous component 13) is disposed on the substrate 11. Therefore, the heat dissipation paths of both the first luminous component 12 and the second luminous component 13 should go through the ceramic substrate, the MCPCB, and the substrate 11 to reach a heat dissipation component. Due to the long heat dissipation path, the overall heat dissipation efficiency of “the automobile lighting device or the light source module thereof” needed to be improved. As stated above, a distance between a luminous surface of the first luminous component 12 and a luminous surface of the second luminous component 13 is not the shortest, which causes the disadvantages of large volume and low luminous efficiency. Moreover, as disclosed in Taiwan Patent Publication No. M536321, the entire structure including the reflective shell, the shield, the lens, and the luminous component was all disposed on the substrate 11. Therefore, the substrate 11 must support the weight of the entire structure and act as a heat transfer medium at the same time. Furthermore, due to the long distance between the first luminous component 12 and the second luminous component 13, the luminous surface of the first luminous component 12 needs to be fixed near the referenced axis to promote the luminous efficiency of low-beam illumination. As a result, the luminous surface of the second luminous component 13 would be away from the location of the high beam filament of the existing tungsten halogen lamp, halogen lamp, or HID lamp, leading to the low luminous efficiency of high-beam illumination.